Abstract: It is proposed by the authory that from the point of view of mechanics, clay soil can be regarded as a elasto—viscous and plastic combination. In order to prove it may be correct A lot of compression tests are carried out by the auther, and she proposed a mechanic model of shanghai remodel soil, so as to describe the deformation characteristics of this soil. In this paper, the concept of proportion (time) element and generalized (positive) Riemann function is first introduced in the model. The theoretical value of this model is coincident with the result of tests, and some other mechanical indexes of the soil can be predicated theoretically by this model.